diff --git a/include/net/sch_generic.h b/include/net/sch_generic.h index 4d2b37226e75..98c10a28cd01 100644 --- a/include/net/sch_generic.h +++ b/include/net/sch_generic.h @@ -30,7 +30,6 @@ struct qdisc_rate_table { enum qdisc_state_t { __QDISC_STATE_SCHED, __QDISC_STATE_DEACTIVATED, - __QDISC_STATE_RUNNING, }; struct qdisc_size_table { @@ -102,6 +101,7 @@ struct Qdisc { refcount_t refcnt; spinlock_t busylock ____cacheline_aligned_in_smp; + spinlock_t seqlock; }; static inline void qdisc_refcount_inc(struct Qdisc *qdisc) @@ -111,17 +111,17 @@ static inline void qdisc_refcount_inc(struct Qdisc *qdisc) refcount_inc(&qdisc->refcnt); } -static inline bool qdisc_is_running(const struct Qdisc *qdisc) +static inline bool qdisc_is_running(struct Qdisc *qdisc) { if (qdisc->flags & TCQ_F_NOLOCK) - return test_bit(__QDISC_STATE_RUNNING, &qdisc->state); + return spin_is_locked(&qdisc->seqlock); return (raw_read_seqcount(&qdisc->running) & 1) ? true : false; } static inline bool qdisc_run_begin(struct Qdisc *qdisc) { if (qdisc->flags & TCQ_F_NOLOCK) { - if (test_and_set_bit(__QDISC_STATE_RUNNING, &qdisc->state)) + if (!spin_trylock(&qdisc->seqlock)) return false; } else if (qdisc_is_running(qdisc)) { return false; @@ -138,7 +138,7 @@ static inline void qdisc_run_end(struct Qdisc *qdisc) { write_seqcount_end(&qdisc->running); if (qdisc->flags & TCQ_F_NOLOCK) - clear_bit(__QDISC_STATE_RUNNING, &qdisc->state); + spin_unlock(&qdisc->seqlock); } static inline bool qdisc_may_bulk(const struct Qdisc *qdisc) diff --git a/net/sched/sch_generic.c b/net/sched/sch_generic.c index ff3ce71aec93..a126f16bc30b 100644 --- a/net/sched/sch_generic.c +++ b/net/sched/sch_generic.c @@ -858,6 +858,11 @@ struct Qdisc *qdisc_alloc(struct netdev_queue *dev_queue, lockdep_set_class(&sch->busylock, dev->qdisc_tx_busylock ?: &qdisc_tx_busylock); + /* seqlock has the same scope of busylock, for NOLOCK qdisc */ + spin_lock_init(&sch->seqlock); + lockdep_set_class(&sch->busylock, + dev->qdisc_tx_busylock ?: &qdisc_tx_busylock); + seqcount_init(&sch->running); lockdep_set_class(&sch->running, dev->qdisc_running_key ?: &qdisc_running_key); @@ -1097,6 +1102,10 @@ static void dev_deactivate_queue(struct net_device *dev, qdisc = rtnl_dereference(dev_queue->qdisc); if (qdisc) { + bool nolock = qdisc->flags & TCQ_F_NOLOCK; + + if (nolock) + spin_lock_bh(&qdisc->seqlock); spin_lock_bh(qdisc_lock(qdisc)); if (!(qdisc->flags & TCQ_F_BUILTIN)) @@ -1106,6 +1115,8 @@ static void dev_deactivate_queue(struct net_device *dev, qdisc_reset(qdisc); spin_unlock_bh(qdisc_lock(qdisc)); + if (nolock) + spin_unlock_bh(&qdisc->seqlock); } }